Plastic extrusion gun



Sept. 18, 1951 w. R. MYERS ETAL PLASTIC EXTRUSION GUN 2 Sheets-Sheet 1 Filed Oct. 3, 1949 u u... ow

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Sept. 18, 1951 w. R. MYERS ET AL 2,557,960

' PLASTIC EXTRUSION GUN Filed Oct. 5, 1949 j 2 Sheets-Sheet 2 I I I I l y 'IIIIIA J (III,

Albert 5. Ten/1am v INVENTORS.

Patented Sept. 18, 1951 UNITED STATES PATENT EOFFICE PLASTIC 'EXTR'USION GUN William R, Myers, Charleston, aid Albert .s. Tennant, South Charleston, W. Va.

Application'Oc'tober 3, 1949,Se1'ia'l'No. 119,232

S-LIaims. 1

This invention relates to a gun type instrument for melting and-extruding plastic material, the instrument being primarily designed for use in the manufacture of fishing flies by applying the molten plastic material to fishhooks to form zthereon elements simulating the body, legs-or feelers, and-other members of insects.

The primary object of the invention is to provide a comparatively simple and eflicient instrument of the above kind by means of which the plastic material maybe readily melted and readily applied to the hooks or other objects as desired.

Another object is to provide an instrument of the above kind including a body portion provided 'with a depending hollow handle and formed with a cylindrical heating chamber in which the plastic material is melted, said chamber having a restricted outlet passage at its front end, a "magazine for plastic material mounted in the handle and having means to feed the material into the heating chamber, piston means for forcing the molten material from said chamber through said passage, and a trigger openedspring closed valve for cont-rolling the flow of molten material through'said passage.

A further object is to provide a magazine adapted to'receive plastic material in ribbon form and including means to feed such material into thelheating chamber.

:Still another object .is :to provide novel piston means for forcing the molten material from the heating chamber.

Other objects and features of the invention will become :apparent from the following de- 'scription when considered with the accompanying drawings, inwhich: V

Figure 1 is a central longitudinal (sectional view of a plastic extrusion-gun embodying the present invention;

.YFrigureZ is a transverse vertical section thereof, taken substantially on the line 2-2 ofFigure 1;

Figure .3 showson azreduced scale :the rear 'portion of the gun shown in Figure 1, conditioned to use fluid pressure for operating the piston which .forces the .molten material from :the .heating chamber;

Figure 4 is a fragmentary side elevational view of the handle'portion of the gun having a modifiedform of magazine;

. Figure 5 is a vertical transverse section taken on the line 5-5 of Figure 4; I

Figure 6 is a horizontal section taken on th :line 6&6 o'f Figure5;

Figure 7 is ia'lview somewhat similar to Figure many closes the valve l6.

:2 r 3 showing a modified form of piston means for forcing the molten material from the heatin chamber;

-8 communicating with thesinterior .of said :han-

die, and an inner-member 9 disposed and supported in spaced relation to and within the casing :6

and formed with a rear cylindrical heating chamher [0, a restricted outlet passage H leading from the front-o'f chamber 10 through the front -endrof said member 9, and a bottom linlet nipp'le l2 communicating with the chamber I0 near the rear end of the latter and depending zin registry with the opening 8. A :heating element .or coil 13 surrounds the member 9 and is embedded in a packing of heat insulating material I4 provided in the space between-the casing 6 and member -13 'to prevent dissipation of heat from the element 13 to casing '6. The ends of element 133 are connected to the wires of a conductor cord 15 which leads "through the handle I, and current supplied ;to the element I3 by way of cord limaybe suit- .ably controlled and regulated.

Flow of material from chamber '10 through passage H is controlled by a valve l6 slidably mounted in the front part of member 9. crank lever 11 is pivotally mounted on the bot- A ;bell

tom of casing 6 and operatively connected atone end to valve 16 through a pin and slot connection -18. Pivoted at its upper end as at l9 to handle TI :and movable in aslot 20 provided in the upper front portion of said handle is a trigger 2| which is connected :to the other end of lever H by a link 22. A'spring 23 acting upon lever ll *nor- A suitable discharge nozzle or tip 24 has a reduced end removably threaded into the frontend of member '9 with its bore 25 aligned with passage H, ,:as shown in 'Figure'l.

forwardly to force molten plastic material from said chamber through passage II and bore-25 of the tip 24. Piston 29 has a rearwardlyextending rod 30 movable through opening 28 and provided on its rear end with a small plunger-31. "The 3 plunger 3| is slidable in a cylinder 32 adjustably threaded through a central opening in the rear end of the extension 26 and having an operating knob 32. As shown in Figure 1, a helical compression spring 33 may be placed in the cylinder 32 between the rear end of the latter and plunger 3| so that said spring may be placed under compression by screwing said cylinder forwardly to move the plunger 3| and the piston 29 in a similar direction so as to force the material from chamber I0. It will be apparent that piston 29 may be retracted by screwing the cylinder 32 rearwardly to relieve the spring 33 of compression and draw the plunger 3| rearwardly. However, the spring 33 may be dispensed with, and pressure fluid may be used to actuate plunger 3| for moving piston 29 to force the molten material from chamber H], as shown in Figure 3. For this purpose, the cylinder 32 has an axial inlet passage 34 for pressure fluid, through its rear portion,

and the rear end of this passage is enlarged and threaded to selectively detachably receive a closure plug 35 or the end coupling 36 of a pressure fluid supply hose 3?. The plug 35 is used when spring 33 is employed, and said plug is removed when-spring 33 is dispensed with and the hose 3'! is coupled to cylinder 32. In the latter case, cylinder 32 is screwed forwardly to dispose plunger 3| at the rear end of cylinder 32 when piston 29 is retracted, fluid being exhausted from cylinder 32 behind plunger 3| through hose 31. It is then simply necessary to supply pressure fluid to cylinder 32 from hose3"! to move the plunger 3| forwardly, thereby correspondingly moving piston 29 to force the material from chamber l0. Piston 29 may be retracted by screwing the cylinder-32 rearwardly to the position of Figure 3 with the plunger 3| engaged with the removable front end wall 38 of the cylinder 32.

'Mounted in the handle I is a magazine to receive plastic material to be melted and extruded, and means is provided to feed such material from the magazine into the chamber l9 ahead of piston 29 when the latter is in retracted position behind the nipple l2 through which the material is fed fromfthe magazine. Figures 1 and 2, the magazine may consist of a cylindrical tube 39 threaded at its upper end into nipple i2 and extending through an opening 40 in the lower end of handle I, said tube having a lateral opening 4| below. the handle through which the plastic material 42, in ribbon or like form, may be introduced into the tubular magazine. Journaled" in the tubular magazine 39 is feeding element consisting of a shaft having a spiral peripheral groove 44 from end to end thereof adapted to receive the plastic ribbon 42. The shaft 43 has a knob 45 on its lower end to facilitate turning thereof so as to draw the plastic ribbon into the magazine from'a suitable source and to feed it into the chamber III as needed.

In use, piston 29 is retracted, and the plastic material is fed'from the magazine into chamber In until the latter is filled, the element |3 having been energized to melt the plastic material as it,

enters the chamber l0. Trigger 2| is then operat- 'ed to open valve I5, and piston 29 is caused to move forwardly to force the molten plastic material from chamber l through passage and the bore 25 of nozzle 24. The material is applied as it emerges from nozzle 26 according to the operation being performed. When forming elements simulating members of insects in the manufacture of fishing flies, the plastic material used is polyethylene or like material which cools and begins As shown more clearly in 4 to solidify as it emerges from the nozzle or tip of the gun.

As shown in Figures 7 and 8, another type of means may be provided for actuating piston 29. In this embodiment, the body extension 26 has a transverse plate 46 slidable therein and prevented from turning by diametric pins 41 carried by said plate and slidably projecting into longitudinal slots 48 of said extension. The rod 39' of piston 29 is swivelled at 49 to the latter, as well as being adjustably threaded at 50 through plate 46 and slidable through the rear end of extension 26' as at 5|. The projecting rear end of rod 39 has a knob 52, and a helical compression spring 53 is disposed about rod 39' between plate 46 and the rear end of extension 26'. In use, rod 39 is threaded rearwardly through plate 46 to retract piston 29. By turning rod 39 while holding piston 29 retracted, plate 46 may be moved rearwardly to compress spring 53 so that when rod 30' is released, said spring will move piston 29 forwardly to force the molten material from chamber Hi.

If desired, the gun may be provided, as shown in Figures 4 to 5 inclusive, with a'magazine adapted to receive plastic material in stick form. This magazine consists of a tube 39 having a plug 54 swivelled on its lower end which is screwed into the lower end of handle 1'. Disposed in the tube 39 is a spring-pressed follower 55 whose actuating spring 56 forces the same upwardly to move the plastic stick 51 into chamber l0. Means 58 is provided to latch the follower in lowered position until it is desired to feed the stick upwardly. A finger piece 59 is carried by handle I" to release the latch means 58. When the piston 29 is in retracted position, latch means 58 is released so that follower 55 will feed the stick 51 upwardly,

the stick being melted, as it enters chamber ill, by the element l3. The magazine 39' is'removable from handle I for retraction of follower 55 and reception of anew stick of plastic material.

From the foregoing description, the nature and advantages of the present invention will be apparent. Further modifications and structural changes are contemplated within thespirit of the invention as claimed.

ing chamber, power means to projectthe piston for forcing molten plastic material fromsaid heating chamber through. said outlet passage,

:manually operable means to retract said piston.

a spring-closed valve for controlling flow of molten material through said outlet passage, and a trigger carried by the handle and operatively connected to said valve. 5

2. A plastic extrusion gun comprising a body portion provided with a depending hollow handle and formed with a cylindrical heating chamber and a front restricted outlet passage, heating means for melting plastic material in said heating chamber, a magazinefor plastic material mounted in the. handle and communicating at its upper end with said heating chamber, feeding means to feed plastic material from the magazine into said heating chamber, piston means for forcing molten plastic material from said heating chamber through said outlet passage, a springclosed valve for controlling flow of molten material through said outlet passage, and a trigger carried by the handle and operatively connected to said valve, said magazine having an inlet opening near its lower end through which the plastic material in ribbon form may be introduced, said feeding means comprising a rotatable shaft journaled in the magazine and having a spiral peripheral groove to receive the plastic ribbon.

3. A plastic extrusion gun comprising a body portion provided with a depending hollow handle and formed with a cylindrical heating chamber and a front restricted outlet passage, heating means for melting plastic material in said heating chamber, a magazine for plastic material mounted in the handle and communicating at its upper end with said heating chamber, mechanical feeding means in the magazine to feed lastic material upwardly from the magazine into said heating chamber, piston means for forcing molten plastic material from said heating chamber through said outlet passage, a spring-closed valve for controlling flow of molten material through said outlet passage, a trigger carried by the handle and operatively connected to said valve, and a hollow extension removably secured on the rear of the body portion and having a transverse wall closing the rear end of the heating chamber, said piston means comprising a piston reciprocable in the heating chamber and retractible rearwardly of the outlet of the magazine, and operating means for the piston carried by said extension, said operating means including power means to project and manually operable means to retract the piston.

4. A plastic extrusion gun comprising a body portion provided with a depending hollow handle and formed with a cylindrical heating chamber and a front restricted outlet passage, heating means for melting plastic material in said heating chamber, a magazine for plastic material mounted in the handle and communicating at its upper end with said heating chamber, feeding means to feed plastic material from the magazine into said heating chamber, piston means for forcing molten plastic material from said heating chamber through said outlet passage, a

spring-closed valve for controlling How of molten material through said outlet passage, and a trigger carried by the handle and operatively connected to said valve, and a hollow extension removably secured on the rear of the body portion and having a transverse wall closing the rear end of the heating chamber, said piston means comprising a piston reciprocable in the heating chamber and retractible rearwardly of the outlet of the magazine, a cylinder threaded through the rear end of said extension for manual adjustment longitudinally of the same, a plunger reciprocable in said cylinder, a rod connecting the piston and the plunger, and means to force the plunger forwardly to similarly move the piston, said cylinder being manually movable rearwardly to retract the piston.

5. A plastic extrusion gun comprising a body portion provided with a depending hollow handle and formed with a :ylindrical heating chamber and a front restricted outlet passage, heating means for melting plastic material in said heating chamber, a magazine for plastic material mounted in the handle and communicating at its upperend with said heating chamber, feeding means to feed plastic material from the magazine into said heating chamber, piston means for forcing molten plastic material from said heating chamber through said outlet passage, a spring-closed valve for controlling flow of molten material through said outlet passage, and a trigger carried by the handle and operatively connected to said valve, said magazine being adapted to receive a stick of plastic material, said feeding means comprising a spring-pressed follower movable in the magazine, latching means to latch the follower in retracted position, and means carried by the handle for releasing said latching means.

WILLIAM R. MYERS. ALBERT S. TENNANT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,430,533 Brown Oct. 3, 1922 1,883,282 Zerk Oct. 18, 1932 2,107,686 Bramsen et a1. Feb. 8, 1938 2,437,264 Manning Mar. 9. 1948 

